In Thinking Fast and Slow, Daniel Kahneman features one of my favorite experiments ever conceived. It involves the natural bias we all feel towards familiarity. As something becomes familiar to us, it becomes comfortable. That comfort reduces uncertainty and creates “cognitive ease.” Cognitive ease is a sign of firm understanding; it’s what allows us to recite something from memory, no matter how fallible it might be. As something becomes more memorable, more familiar, more cognitively-easy to recall, it becomes the sort of thing that we accept as true.

In other words, the effect of “brainwashing” and indoctrination has its roots in regular exposure to the point of familiarity and thus belief. But don’t take my words for it. Consider the description of the experiment that illustrates this. As written by our author:

People who were repeatedly exposed to the phrase “the body temperature of a chicken” were more likely to accept as true the statement that “the body temperature of a chicken is 144 degrees”.

In case anyone is confused, there is no warm-blooded animal that has a body temperature of 144 degrees. The air temperature of the planet has never reached that level of heat. And yet, with enough priming of an unrelated phrase about chickens, people will naturally—comfortably—associate the two ideas.

More from Kahneman:

A reliable way to make people believe in falsehoods is frequent repetition, because familiarity is not easily distinguished from truth. Authoritarian regimes and marketers have always known this fact. But it was psychologists who discovered that you do not have to repeat the entire statement of a fact or idea to make it appear true.

The key part is the phrase “familiarity is not easily distinguished from the truth”. How does this happen? It comes back to the idea of “cognitive ease”. When we lack a balanced way of thinking, it’s because we rely more than we should on our System 1 faculties. It is a marvelous way of conserving energy.

Over time, a persistent barrage of messages can wear down even the most resistant audience if there is no sustained counter-argument. This is because the lack of counter-argument reduces the ability for System 2 to hold onto uncertainty. Without uncertainty, via competing arguments, System 2 thinking has no reason to be engaged and the persistent message becomes familiar, singular, and is then accepted in System 1 as a powerful association, at minimum, or an absolute belief at worst.

Imagine someone arguing that a chicken’s body temperature is hotter than medium-well steak. It sounds crazy but it’s entirely possible. After all, as analyzed before, a steady flow of information, any kind of information, can be highly influential.

I think it comes down to diversity in our information diet. Just as surely as a balanced food diet includes a broad variety of plants, grains, fats, proteins, and the occasional sugary indulgence, an information diet requires a broad variety of sources on a wide range of topics. The diversity strengthens the ability to hold multiple points of view, stay out of the filter bubble, and maintain System 2 thinking with multiple perspectives.

Obviously, this applies to social media. As Bill Gates has already said:

(Technologies such as social media) lets you go off with like-minded people, so you’re not mixing and sharing and understanding other points of view … It’s super important. It’s turned out to be more of a problem than I, or many others, would have expected.

But it also applies to our local circles. Perhaps even more so. There’s an old adage that I’ve heard so much that I’m starting to really believe it (pun intended). As proclaimed by Jim Rohn long ago: You are the average of the five people you spend the most time with.

It’s about their attitudes. Take the optimism/pessimism divide. Spend enough time with pessimists and you will likely become more pessimistic. Unless you’re aware of this tendency.

Most people are not.

And even when you are aware of the tendency and fight to cling to your optimism, being an outlier has real cost. It does not create “cognitive ease”. And as we’ve seen with years of demographic shifts, people will go to great lengths to find their “cognitive ease” by physically relocating to places where they can find others like themselves.

This is highlighted to great effect by a fantastic book called The Big Sort. I highly recommend it. And if you can’t find the time to read it, just look at the articles written lately about the urban/rural divide that manifested in the midterm elections. Clusters happen for a reason; people are naturally drawn to others like themselves lest they become more like those around them.

This is perfectly understandable. I’ve lived in all four time zones with some who are more like me than others. I understand the benefit. But if we seek such comfort and familiarity to the greatest extent possible, a cognitive ease will set in. We will build our exchanges with people like us and formalize our familiar “beliefs we hold as self-evident”. Those beliefs might not get tested as rigorously and we may end up thinking that a chicken’s body temperature is hotter than Death Valley. We and our friends might fight furiously for that belief amidst all skeptics.

Regardless of where one lives or who you surround yourself with, a clear antidote to this tendency is available to us all. Mindful consumption of information helps, a’la the information diet and cultivated information flows. But more importantly, the ability to always engage in this information via System 2 thinking is even better. This requires nothing more than a willingness to seek fact over opinion. To become more “factful” in the way that Has Rosling defines in Factfulness (my review is here).

We can’t question everything. We can’t know everything. But we can’t surrender to that reality and just do what is cognitively easy. Doing so leaves us more open to suggestion than we may think.